Preheat oven to 350 degrees. Grease the bottom and 1/2 inch up the sides of a 13x9x2 inch baking pan; set aside. In a large bowl combine flour, brown sugar, and salt. Cut in butter until mixture resembles coarse crumbs; set aside 1/2 cup. Stir baking powder, baking soda, cinnamon, and nutmeg into remaining crumb mixture.

In a medium bowl combine eggs and buttermilk. Add egg mixture all at once to flour mixture, stirring just until moistened. Spoon batter into prepared pan. Stir together reserved crumb mixture and nuts; sprinkle over batter.

Bake for 35-40 minutes or until a wooden toothpick inserted near the center comes out clean. Cool slightly; serve warm.